I have just basic user knowledge of Raspberry but if I understand it correctly, the driver
should allow non-root access to GPIO pins:
https://github.com/raspberrypi/linux/blob/rpi-4.4.y/drivers/char/broadcom...
I use Rpi3 with Fedora 25 for running Home Assistant and I would like to meassure
temperature and humidity directly on Rpi3. I have discovered the gpiomem module while
looking into the source code of DHT22 driver from Adafruit:
https://github.com/adafruit/Adafruit_Python_DHT/blob/master/source/Raspbe...
int fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
Then I googled little bit more and realized, that the gpiomem driver is used quite often:
https://www.npmjs.com/package/rpio
http://wiringpi.com/wiringpi-update-to-2-29/
Michal